Isolation structure for bond pad structure

ABSTRACT

Various embodiments of the present disclosure are directed towards a semiconductor device structure including a bond pad isolation structure. A semiconductor substrate has a back-side surface and a front-side surface opposite the back-side surface. A bond pad extends through the semiconductor substrate. The bond pad isolation structure is disposed within the semiconductor substrate. The bond pad isolation structure extends from the front-side surface to the back-side surface of the semiconductor substrate and continuously extends around the bond pad.

BACKGROUND

Integrated circuits (ICs) with image sensors are used in a wide range ofmodern day electronic devices, such as cameras and cell phones, forexample. Complementary metal-oxide semiconductor (CMOS) devices havebecome popular IC image sensors. Compared to charge-coupled devices(CCD), CMOS image sensors are increasingly favored due to low powerconsumption, small size, fast data processing, a direct output of data,and low manufacturing cost. Some types of CMOS image sensors includefront-side illuminated (FSI) image sensors and back-side illuminated(BSI) image sensors.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 illustrates a cross-sectional view of some embodiments of anintegrated chip including a bond pad extending through a semiconductorsubstrate.

FIG. 2 illustrates a top view of some alternative embodiments of the ICof FIG. 1, as indicated by the cut-lines in FIGS. 1-2.

FIG. 3 illustrates a cross-sectional view of some embodiments of animage sensor including a bond pad laterally offset from a plurality ofphotodetectors.

FIG. 4 illustrates a top view of some alternative embodiments of theimage sensor of FIG. 3, as indicated by the cut-lines in FIGS. 3-4.

FIGS. 5, 6A, 6B, 7, and 8 illustrate cross-sectional views of somealternative embodiments of a bond pad isolation structure surrounding abond pad.

FIGS. 9-21 illustrate a series of cross-sectional views of someembodiments of a first method for forming a bond pad isolation structuresurrounding a bond pad.

FIG. 22 illustrates a block diagram of some embodiments of the firstmethod of FIGS. 9-21.

FIGS. 23-30 illustrate a series of cross-sectional views of someembodiments of a second method for forming a bond pad isolationstructure surrounding a bond pad.

FIG. 31 illustrates a block diagram of some embodiments of the secondmethod of FIGS. 23-30.

FIGS. 32-38 illustrates a series of cross-sectional views of someembodiments of a third method for forming a bond pad isolation structuresurrounding a bond pad.

FIG. 39 illustrates a block diagram of some embodiments of the thirdmethod of FIGS. 32-38.

DETAILED DESCRIPTION

The present disclosure provides many different embodiments, or examples,for implementing different features of this disclosure. Specificexamples of components and arrangements are described below to simplifythe present disclosure. These are, of course, merely examples and arenot intended to be limiting. For example, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed between the first and second features, such thatthe first and second features may not be in direct contact. In addition,the present disclosure may repeat reference numerals and/or letters inthe various examples. This repetition is for the purpose of simplicityand clarity and does not in itself dictate a relationship between thevarious embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Integrated chips typically comprise a plurality of metal interconnectlayers arranged along a front-side of a substrate. The plurality ofmetal interconnect layers are configured to electrically connect devices(e.g., transistors, photodetectors, etc.) arranged within the substratetogether. Back-side illuminated CMOS image sensors (BSI-CISs) comprisephotodetectors arranged within the substrate in proximity to a back-sideof the substrate, so that the photodetectors are able to receive lightalong the back-side of the substrate. By receiving light along theback-side of the substrate, incident light does not traverse theplurality of metal interconnect layers, thereby increasing an opticalefficiency of the photodetectors.

By virtue of the BSI-CISs receiving light along a back-side of asubstrate, substrates having BSI-CIS are often placed within a packagingstructure in a front-side down configuration that exposes the back-sideof the substrate. Because the back-side of the substrate is exposed,bond pads are often arranged along the back-side of the substrate andare connected to metal interconnect layers. The bond pads may have anumber of different configurations. For example, the bond pad may bedisposed within a bond pad opening that extends through the front-sideof the substrate to the back-side of the substrate. To electricallyisolate the bond pad from the substrate, a dielectric structure isdisposed along sidewalls of the substrate that define the bond padopening. However, disposing the dielectric structure along the bond padopening increases complexity, time, and cost associated with fabricatingthe BSI-CIS. Further, a top surface of the bond pad may be disposedbelow the back-side of the substrate. This may increase light receivedby the photodetectors; nevertheless this will decrease a reliability ofa bond between the bond pad and another bonding structure. Furthermore,the bond pad may comprise an upper conductive segment extending over theback-side of the substrate, thereby increasing a reliability of the bondbetween the bond pad and another bonding structure. However, in suchembodiments, the upper conductive segment may reflect light away fromthe photodetectors, thereby decreasing a reliability and/or a quality ofimages reproduced from the photodetectors.

Accordingly, in some embodiments, the present disclosure relates to anintegrated chip including a bond pad isolation structure surrounding abond pad. The integrated chip includes a plurality of photodetectorsarranged within a substrate. A bond pad region extends through thesubstrate, at a location laterally offset from the photodetectors, to ametal interconnect wire arranged within an interconnect dielectricstructure disposed along a front-side of the substrate. The bond pad isdisposed within the bond pad region and extends from the front-side ofthe substrate to a back-side of the substrate and is electricallycoupled to the metal interconnect wire. In some embodiments, the bondpad directly contacts an upper surface of the substrate and contactssidewalls of the substrate. The bond pad isolation structure has aring-shape and laterally surrounds the bond pad. Further, the bond padisolation structure extends from the back-side to the front-side of thesubstrate, thereby electrically isolating the bond pad from devices(e.g., the photodetectors and/or transistors) disposed on and/or withinthe substrate. The bond pad contacting the substrate decreasescomplexity, time, and cost associated with forming the bond pad.Further, the bond pad isolation structure prevents “leakage” (i.e., aflow of current) from the bond pad to devices disposed on and/or withinthe substrate.

FIG. 1 illustrates a cross-sectional view of some embodiments of anintegrated chip 100 having a bond pad 116 disposed within a bond padregion 101 b.

The integrated chip 100 includes an interconnect structure 104 disposedalong a front-side 110 fs of a semiconductor substrate 110 (e.g., asilicon substrate). The interconnect structure 104 overlies a carriersubstrate 102 (e.g., a silicon substrate), wherein the interconnectstructure 104 is disposed between the semiconductor substrate 110 andthe carrier substrate 102. The interconnect structure 104 includes aplurality of interconnect layers arranged within an interconnectdielectric structure 103. The plurality of interconnect layers alternatebetween conductive wires 108 and conductive vias 106. The conductivewires 108 are configured to provide a lateral connection (i.e., aconnection parallel to an upper surface of the carrier substrate 102),whereas the conductive vias 106 are configured to provide for a verticalconnection between adjacent conductive wires 108. The conductive wires108 include an upper conductive wire layer 108 a. A dielectric structure118 overlies a back-side 110 bs of the semiconductor substrate 110. Ashallow trench isolation (STI) structure 112 is disposed within thesemiconductor substrate 110 and extends along an upper surface of theinterconnect dielectric structure 103.

The bond pad region 101 b extends through the semiconductor substrate110, at a location laterally offset from a device region 101 a, to theupper conductive wire layer 108 a. In some embodiments, the deviceregion 101 a includes one or more semiconductor devices 120 (e.g.,transistor(s), resistor(s), varactor(s), etc.) and/or photodetectors(not shown) disposed within and/or on the semiconductor substrate 110. Abond pad 116 and a bond pad isolation structure 114 are disposed withinthe bond pad region 101 b. The bond pad 116 includes an upper conductivebody 116 a and conductive protrusions 116 b underlying the upperconductive body 116 a. The upper conductive body 116 a comprises a samematerial (e.g., aluminum copper) as the conductive protrusions 116 b. Insome embodiments, the upper conductive body 116 a directly overlies anddirectly contacts an upper surface 110 us of the semiconductor substrate110. In such embodiments, the conductive protrusions 116 b directlycontact sidewalls of the semiconductor substrate 110 and extend from theupper conductive body 116 a to the upper conductive wire layer 108 a.Further, the upper conductive body 116 a has sidewalls that define padopenings 116 o overlying the conductive protrusions 116 b. The bond pad116 may be configured to electrically couple the one or moresemiconductor devices 120 to another integrated chip (not shown). Insome embodiments, the upper conductive body 116 a is laterally offsetfrom an inner sidewall 110 is of the semiconductor substrate 110 by anon-zero distance.

A bond pad isolation structure 114 is laterally offset from andsurrounds outer sidewalls of the bond pad 116. In some embodiments, thebond pad isolation structure 114 comprises a material (e.g., silicondioxide) different from the semiconductor substrate 110. The bond padisolation structure 114 may extend from the front-side 110 fs to theback-side 110 bs of the semiconductor substrate 110. In someembodiments, the bond pad isolation structure 114 has a height h₁ thatis greater than or equal to a height h₂ of the semiconductor substrate110. The bond pad isolation structure 114 is configured to electricallyisolate the bond pad 116 from other devices (e.g., the semiconductordevices 120) and/or doped regions (not shown) disposed within and/or onthe semiconductor substrate 110. This may mitigate and/or prevent a“leakage” (i.e., a flow of current) between the bond pad 116 and theother devices and/or doped regions disposed within and/or on thesemiconductor substrate 110, thereby increasing a reliability andendurance of the integrated chip 100. Further, in some embodiments, whenthe bond pad 116 directly contacts the semiconductor substrate 110complexity, cost, and time associated with forming the integrated chip100 may be reduced.

FIG. 2 illustrates a top view 200 of some alternative embodiments of theintegrated chip 100 of FIG. 1, as indicated by the cut-lines in FIGS. 1and 2. For ease of illustration, the dielectric structure 118 of FIG. 1has been omitted from the top view 200 of FIG. 2.

As illustrated in FIG. 2, the bond pad isolation structure 114 has aring like shape, where inner sidewalls of the bond pad isolationstructure 114 completely surround outer sidewalls of the bond pad 116.The inner sidewalls of the bond pad isolation structure 114 arelaterally offset from outer sidewalls of the bond pad isolationstructure 114 by a distance d₁. In some embodiments, the distance d₁ isnon-zero. When viewed from above, the bond pad isolation structure 114has a rectangular/square shape with rounded edges; however the bond padisolation structure 114 may have other shapes, such as acircular/elliptical shape. When viewed from above, the bond pad 116 hasa rectangular/square shape with rounded edges; however the bond pad 116may have other shapes, such as a circular/elliptical shape. In someembodiments, a shape of the bond pad isolation structure 114 correspondsto a shape of the bond pad 116. Further, the sidewalls of the bond pad116 defining the pad openings 116 o are laterally offset from oneanother by a non-zero distance. In some embodiments, a solder bump (notshown) may be disposed laterally between the pad openings 116 o. Whenviewed from above, the pad openings 116 o may, for example, have asquare/rectangular shape. The bond pad isolation structure 114continuously wraps around the outer sidewalls of the bond pad 116 andextends from the front-side (110 fs of FIG. 1) to the back-side (110 bsof FIG. 1) of the semiconductor substrate 110. Thus, the bond padisolation structure 114 electrically isolates the bond pad 116 fromother semiconductor devices and/or doped regions disposed within and/oron the semiconductor substrate 110. The STI structure 112 directlyunderlies the bond pad 116. In some embodiments, outer sidewalls of thebond pad 116 are laterally spaced between outer sidewalls of the STIstructure 112.

FIG. 3 illustrates a cross-sectional view of some embodiments of animage sensor 300 including a bond pad 116 laterally offset from aplurality of photodetectors 302.

A semiconductor substrate 110 overlies a carrier substrate 102. In someembodiments, the semiconductor substrate 110 and/or the carriersubstrate 102 may respectively, for example, be a bulk substrate (e.g.,a bulk silicon substrate), a silicon-on-insulator (SOI) substrate, orsome other suitable substrate. The plurality of photodetectors 302 aredisposed within the semiconductor substrate 110. In some embodiments,the photodetectors 302 respectively extend from a back-side 110 bs ofthe semiconductor substrate 110 to a point below the back-side 110 bs.In further embodiments, the point is at a front-side 110 fs of thesemiconductor substrate 110, which is opposite the back-side 110 bs ofthe semiconductor substrate 110. An interconnect structure 104 isdisposed along the front-side 102 fs of the semiconductor substrate 110.The interconnect structure 104 includes an interconnect dielectricstructure 103, a plurality of conductive wires 108, and a plurality ofconductive vias 106. The semiconductor substrate 110 is bonded to thecarrier substrate 102 by way of the interconnect structure 104. In someembodiments, the conductive wires 108 and/or the conductive vias 106 mayrespectively, for example, be or comprise aluminum, copper, aluminumcopper, tungsten, or the like. In some embodiments, the interconnectdielectric structure 103 may, for example, comprise one or moredielectric layers (e.g., silicon dioxide).

A dielectric structure 118 overlies the back-side 110 bs of thesemiconductor substrate 110. In some embodiments, the dielectricstructure 118 includes one or more dielectric layers, such as a firstdielectric layer 304 a, a second dielectric layer 304 b, a thirddielectric layer 304 c, and a fourth dielectric layer 304 d. In someembodiments, the first dielectric layer 304 a may, for example, be orcomprise a metal oxide, such as aluminum oxide, or another suitableoxide. The second dielectric layer 304 b may, for example, be orcomprise a metal oxide, such as hafnium oxide, or another suitableoxide. The third dielectric layer 304 c may, for example, be or comprisea metal oxide, such as tantalum oxide, or another suitable oxide. Thefourth dielectric layer 304 d may, for example, be or comprise an oxide,such as silicon dioxide, another suitable oxide, undoped silicon glass(USG), polysilicon, another suitable dielectric and/or may have athickness within a range of about 500 to 3,000 Angstroms. The dielectricstructure 118 may be configured to protect the back-side 110 bs of thesemiconductor substrate 110.

An etch stop layer 306 overlies the dielectric structure 118. A firstgrid layer 308 overlies the etch stop layer 306, and a second grid layer310 overlies the first grid layer 308. A grid structure 312 includes asegment of the first and second grid layers 308, 310 vertically abovethe photodetectors 302. The grid structure 312 is laterally around andbetween the photodetectors 302 to define a plurality of color filteropenings. A plurality of color filters 314 are arranged within theplurality of color filter openings and overlies the plurality ofphotodetectors 302. The grid structure 312 comprises a dielectricmaterial with a refractive index less than a refractive index of thecolor filters 314. Due to the lower refractive index, the grid structure312 serves as a radiation guide to direct incident electromagneticradiation (i.e., light) to a corresponding photodetector 302. Further,the color filters 314 are respectively configured to block a first rangeof frequencies of the incident electromagnetic radiation while passing asecond range of frequencies (different than the first range offrequencies) of the incident electromagnetic radiation to an underlyingphotodetector 302.

In some embodiments, the etch stop layer 306 may, for example, be orcomprise silicon carbide, silicon nitride, or the like and/or may have athickness of about 1,500 Angstroms. In some embodiments, the first gridlayer 308 may, for example, be or comprise an oxide, such as silicondioxide, or another suitable oxide and/or may have a thickness of about5,600 Angstroms. In further embodiments, the second grid layer 310 may,for example, be or comprise an oxide, such as silicon-oxy-nitride, oranother suitable oxide and/or may have a thickness of about 1,500Angstroms. In yet further embodiments, the first grid layer 308 may beor comprise a metal such as tungsten, another suitable metal, or thelike. In such embodiments, the grid structure 312 may be configured as acomposite grid structure comprising one or more metal layers and one ormore dielectric layers. In further embodiments, the grid structure 312may be configured as a dielectric grid structure comprising one or moredielectric layers.

One or more semiconductor devices 120 (e.g., transistor(s), resistor(s),etc.) may be disposed within and/or on the front-side 110 fs of thesemiconductor substrate. In such embodiments, the one or moresemiconductor devices 120 may, for example, be pixel devices, such as atransfer transistor, a source follower transistor, a reset transistor,etc. The one or more semiconductor devices 120, the photodetectors 302,and the grid structure 312 are laterally arranged within a device region101 a of the image sensor 300. The device region 101 a is laterallyoffset from a bond pad region 101 b of the image sensor 300. A bond pad116 and a bond pad isolation structure 114 are laterally arranged withinthe bond pad region 101 b of the image sensor 300. Thus, in someembodiments, the bond pad 116 and the bond pad isolation structure 114are laterally offset from the photodetectors 302 and/or the one or moresemiconductor devices 120 by a non-zero distance.

The bond pad 116 is configured to electrically coupled the one or moresemiconductor devices 120 and/or the photodetectors 302 to anotherintegrated chip (not shown) by way of the interconnect structure 104. Insome embodiments, the bond pad 116 directly contacts an upper surface110 us of the semiconductor substrate 110 and has protrusions extendingthrough the semiconductor substrate 110 to the upper conductive wirelayer 108 a. In such embodiments, the protrusions directly contactsidewalls of the semiconductor substrate 110 disposed below the uppersurface 110 us of the semiconductor substrate 110. The protrusionsextend through a shallow trench isolation (STI) structure 112 and theinterconnect dielectric structure 103. Further, the bond pad 116 hassidewalls that define pad openings 116 o overlying the protrusions ofthe bond pad 116. In further embodiments, the bond pad 116 is laterallyoffset upper sidewalls of the semiconductor substrate 110 and sidewallsof the dielectric structure 118 by a distance d₂. In some embodiments,the distance d₂ is non-zero, such that the bond pad 116 is may beelectrically isolated from the dielectric structure 118. Further, insuch embodiments, by virtue of the non-zero distance d₂, upper sidewallsof the semiconductor substrate 110 and/or sidewalls of the dielectricstructure 118 may be protected from a bonding process performed on thebond pad 116 (i.e., from a downward force applied to the bond pad 116).This may increase a structural integrity of the image sensor 300. Insome embodiments, a top surface of the bond pad 116 is aligned with atop surface of the dielectric structure 118 (not shown) (e.g., see FIG.5). The bond pad has a bond pad height h_(bp) defined from the uppersurface 110 us of the semiconductor substrate 110 to the top surface ofthe bond pad 116. In some embodiments, the bond pad height h_(bp) isabout 12,000 Angstroms.

The bond pad isolation structure 114 laterally surrounds the bond pad116, wherein the bond pad isolation structure 114 extends from theback-side 110 bs of the semiconductor to a point below the front-side110 fs. Thus, the bond pad isolation structure 114 electrically isolatesthe bond pad 116 from the one or more semiconductor device 120 and/orthe photodetectors 302, thereby preventing a “leakage” (i.e., a flow ofcurrent) between the bond pad 116 and the adjacent devices. Thisincreases a performance, stability, and reliability of the image sensor300. The bond pad isolation structure 114 has a height h₁ that isgreater than a height h₂ of the semiconductor substrate 110. A bottomsurface of the bond pad isolation structure 114 is vertically below thefront-side 110 fs of the semiconductor substrate 110 by a distanced_(v). In some embodiments, the distance d_(v) is non-zero, wherein thebond pad isolation structure 114 extends into the interconnectdielectric structure 103. In some embodiments, if the bottom surface ofthe bond pad isolation structure 114 is above the front-side 110 fs(i.e., the distance d_(v) is negative and/or the height h₁ is less thanthe height h₂) then “leakage” may occur between the bond pad 116 and theone or more semiconductor devices 120 and/or the photodetectors 302,thereby decreasing a performance of the image sensor 300. The bond padisolation structure 114 may, for example, be or comprise an oxide, suchas silicon dioxide, or silicon nitride, silicon oxynitride, or the like.

FIG. 4 illustrates a top view 400 of some alternative embodiments of theimage sensor 300 of FIG. 3, as indicated by the cut-lines in FIGS. 3 and4.

As illustrated in FIG. 4, the bond pad isolation structure 114 has aring like shape, where inner sidewalls of the bond pad isolationstructure 114 completely surround outer sidewalls of the bond pad 116.The outer sidewalls of the bond pad 116 are laterally offset from aninner sidewall 110 is of the semiconductor substrate 110 by a distanced₂. In some embodiments, the distance d₂ is non-zero. The color filters314 are arrange in an array comprising rows and columns and respectivelyoverlie the photodetectors (302 of FIG. 3). In some embodiments, whenviewed from above, the color filters 314 respectively have arectangular/square shape and/or a circular/elliptical shape (not shown).

FIG. 5 illustrates a cross-sectional view of some alternativeembodiments of an integrated chip 500 having a bond pad 116 surroundedby a bond pad isolation structure 114.

A top surface 116 ts of the bond pad 116 and a top surface of thedielectric structure 118 are respectively aligned along a substantiallystraight line 502. In some embodiments, the substantially straight line502 is parallel to the back-side 110 bs of the semiconductor substrate110. In further embodiments, the top surface 116 ts of the bond pad 116is above the top surface of the dielectric structure 118 (not shown).Further, the bond pad isolation structure 114 has slanted sidewalls,wherein a width Wi of the bond pad isolation structure 114 continuouslyincreases from the back-side 110 bs of the semiconductor substrate 110to the front-side 110 fs of the semiconductor substrate 110. In suchembodiments, during a formation of the integrated chip 500, the bond padisolation structure 114 may, for example, have been formed concurrentlywith the STI structure 112, or after forming the STI structure 112 andbefore forming the interconnect structure 104. In some embodiments, forexample, the substantially straight line 502 is configured as a levelhorizontal line. In further embodiments, the substantially straight line502 may vary within a range of −25 to 25 Angstroms or within a range of−5 to 5 Angstroms from a level horizontal line disposed along the topsurface 116 ts of the bond pad 116. In yet further embodiments, an angleis defined between a first point disposed along the substantiallystraight line 502 and a second point disposed along the substantiallystraight line 502, where the first point is laterally offset from thesecond point, and the angle is about 180 degrees.

FIG. 6A illustrates a cross-sectional view of some alternativeembodiments of an integrated chip 600 having a bond pad 116 surroundedby a bond pad isolation structure 114.

The bond pad isolation structure 114 extends from the back-side 110 bsof the semiconductor substrate 110 to a point below the front-side 110fs of the semiconductor substrate 110. In some embodiments, a bottomsurface of the bond pad isolation structure 114 may be aligned with thefront-side 110 fs of the semiconductor substrate 110 (not shown). Thebond pad isolation structure 114 has slanted sidewalls, wherein a widthWi of the bond pad isolation structure 114 continuously decreases fromthe back-side 110 bs of the semiconductor substrate 110 to thefront-side 110 fs of the semiconductor substrate 110. In suchembodiments, during a formation of the integrated chip 600, the bond padisolation structure 114 may, for example, have been formed after formingthe interconnect structure 104.

FIG. 6B illustrates a cross-sectional view of some alternativeembodiments of the integrated chip 600 of FIG. 6A, where the bond padisolation structure 114 is spaced laterally between outer sidewalls ofthe STI structure 112.

FIG. 7 illustrates a cross-sectional view of some alternativeembodiments of an integrated chip 700 having a device region 101 alaterally offset from a bond pad region 101 b.

A device STI structure 702 is disposed within the device region 101 a,wherein the device STI structure 702 comprises a same material as theSTI structure 112. In some embodiments, the device STI structure 702 hasa bottom surface and a top surface that are respectively aligned with abottom surface and a top surface of the STI structure 112. In furtherembodiments, the device STI structure 702 has a ring-shape and surroundsat least one semiconductor device 120 disposed within and/or on thesemiconductor substrate 110. The device STI structure 702 may furtherincrease an electrical isolation between the semiconductor device 120and the bond pad 116. Further, a bottom surface of the bond padisolation structure 114 is aligned with the bottom surface of the STIstructure 112 and/or the bottom surface of the device STI structure 702.In some embodiments, the STI structure 112 continuously extends betweenouter sidewalls of the bond pad isolation structure 114, wherein the STIstructure 112 further increases electrical isolation between the bondpad 116 and other devices disposed on and/or within the semiconductorsubstrate 110 (e.g. the semiconductor device 120, photodetectors (notshown), etc.). In further embodiments, the STI structure 112 and thebond pad isolation structure 114 comprise a same material, wherein thebond pad isolation structure 114 is a protrusion of the STI structure112.

FIG. 8 illustrates a cross-sectional view of some alternativeembodiments of an integrated chip 800 having a bond pad isolationstructure 114 disposed around a bond pad 116.

A first insulator layer 802 is disposed along sidewalls of thedielectric structure 118 and sidewalls of the semiconductor substrate110. The first insulator layer 802 is disposed between the bond pad 116and the upper surface 110 us of the semiconductor substrate 110. Thebond pad 116 includes a conductive body disposed above the upper surface110 us of the semiconductor substrate 110, and conductive protrusionsextending from the conductive body to the upper conductive wire layer108 a. A second insulator layer 804 is disposed along sidewalls of thefirst insulator layer 802 and along sidewalls of the protrusions of thebond pad 116. The second insulator layer 804 is disposed betweensidewalls of the semiconductor substrate 110 and the protrusions of thebond pad 116, wherein the second insulator layer 804 continuouslyextends around the respective protrusions. The first and secondinsulator layers 802, 804 are respectively configured to electricallyisolate the bond pad 116 from the semiconductor substrate 110. Thisfurther increases a performance and reliability of the integrated chip800. In some embodiments, the first insulator layer 802 may, forexample, be or comprise an oxide, such as silicon dioxide, undopedsilicon glass silicon dioxide (USGOX), another suitable oxide, or thelike. In some embodiments, the second insulator layer 804 may, forexample, be or comprise an oxide, such as silicon dioxide, USGOX,another suitable oxide, or the like.

FIGS. 9-21 illustrate cross-sectional views 900-2100 of some embodimentsof a first method of forming an integrated chip including a bond padisolation structure surrounding a bond pad according to aspects of thepresent disclosure. Although the cross-sectional views 900-2100 shown inFIGS. 9-21 are described with reference to a first method, it will beappreciated that the structures shown in FIGS. 9-21 are not limited tothe method but rather may stand alone separate of the method. AlthoughFIGS. 9-21 are described as a series of acts, it will be appreciatedthat these acts are not limiting in that the order of the acts can bealtered in other embodiments, and the methods disclosed are alsoapplicable to other structures. In other embodiments, some acts that areillustrated and/or described may be omitted in whole or in part.

As shown in cross-sectional view 900 of FIG. 9, a semiconductorsubstrate 110 is provided and a masking layer 902 is formed on afront-side 110 fs of the semiconductor substrate 110. In someembodiments, the semiconductor substrate 110 may, for example, be a bulksubstrate (e.g., a bulk silicon substrate), a silicon-on-insulator (SOI)substrate, or some other suitable substrate. A shallow trench isolation(STI) structure 112 is formed on the front-side 110 fs of thesemiconductor substrate 110. In some embodiments, a process for formingthe STI structure 112 may include: selectively etching the semiconductorsubstrate 110 to form a trench that extends into in the front-side 110fs of the semiconductor substrate 110; and filling (e.g., by chemicalvapor deposition (CVD), physical vapor deposition (PVD), atomic layerdeposition (ALD), thermal oxidation, etc.) the trench with a dielectricmaterial (e.g., silicon dioxide, silicon carbide, etc.). In furtherembodiments, the semiconductor substrate 110 is selectively etched byexposing unmasked portions of the semiconductor substrate 110 to one ormore etchants configured to selectively remove unmasked portions of thesemiconductor substrate 110. The masking layer 902 may, for example, beor comprise silicon-oxy-nitride.

As shown in cross-sectional view 1000 of FIG. 10, a deep trenchisolation (DTI) layer 1002 is formed over and into the semiconductorsubstrate 110. In some embodiments, a process for forming the DTI layer1002 includes: forming a second masking layer over the masking layer 902and the STI structure 112; patterning the semiconductor substrate 110and the masking layer 902 according to the second masking layer, therebyforming DTI openings in the semiconductor substrate 110; forming (e.g.,by a plasma-enhanced CVD (PECVD) process, a high aspect ratio process(HARP), PVD, or another suitable deposition process) a DTI material(e.g., silicon oxide, silicon nitride, silicon oxynitride,plasma-enhanced oxide (PEOX), another suitable dielectric material, orthe like) over the semiconductor substrate 110, wherein the DTI materialfills the DTI openings. In some embodiments, forming the DTI materialincludes forming a first dielectric layer (e.g., comprising siliconoxide) over a second dielectric layer (e.g., comprising siliconnitride), the second dielectric layer lines the DTI openings and thefirst dielectric layer fills a remaining portion of the DTI openings. Insome embodiments, a bottom surface of the DTI layer 1002 is disposedabove a back-side 110 bs of the semiconductor substrate 110. In someembodiments, the DTI layer 1002 is formed by, for example, CVD, PVD,ALD, or another suitable deposition process. In some embodiments, theDTI layer 1002 has a height h_(dl) within a range of about 12,000 to15,000 Angstroms or greater than 20,000 Angstroms.

As shown in cross-sectional view 1100 of FIG. 11, a planarizationprocess is performed on the DTI layer (1002, FIG. 10), thereby defininga bond pad isolation structure 114. In some embodiments, theplanarization process includes performing a chemical-mechanicalplanarization (CMP) on the DTI layer (1002, FIG. 10) and/or the STIstructure 112 until the front-side 110 fs of the semiconductor substrate110 is reached. In further embodiments, the planarization process mayremove the masking layer 902. In some embodiments, after performing theplanarization process the bond pad isolation structure 114 has a heighth₁ that is greater than 2 micrometers. In further embodiments, a widthWi of the bond pad isolation structure 114 continuously decreases fromthe front-side 110 fs to a point above the back-side 110 bs of thesemiconductor substrate 110.

In some embodiments, the planarization process includes performing a CMPon the DTI layer (1002, FIG. 10) until a top surface of the STIstructure 112 is exposed, thereby defining the bond pad isolationstructure 114 (not shown). In such embodiments, an upper surface of theSTI structure 112 and an upper surface of the bond pad isolationstructure 114 are respectively vertically offset from the front-side 110fs of the semiconductor substrate 110, as illustrated in thecross-sectional view of FIG. 7. Further, in such embodiments, afterperforming the planarization a removal process is performed to removethe masking layer 902 (not shown).

As shown in cross-sectional view 1200 of FIG. 12, an interconnectstructure 104 is formed on the front-side 110 fs of the semiconductorsubstrate 110. The interconnect structure 104 includes an interconnectdielectric structure 103, a plurality of conductive wires 108, and aplurality of conductive vias 106. In some embodiments, the interconnectdielectric structure 103 may be or comprise one or more inter-leveldielectric (ILD) layers. The one or more ILD layers may, for example, beor comprise an oxide, such as silicon dioxide, or another suitableoxide. In some embodiments, a process for forming the interconnectstructure 104 includes forming the conductive vias 106 and theconductive wires 108 by a single damascene process or a dual damasceneprocess. For example, a first layer of the conductive vias 106 and afirst layer of the conductive wires 108 may respectively be formed by asingle damascene process. Further, in such embodiments, the processincludes forming remaining layers of the conductive wires 108 and theconductive vias 106 by repeatedly performing a dual damascene process.In some embodiments, the conductive wires 108 and/or the conductive vias106 may respectively, for example, be or comprise aluminum, copper,aluminum copper, tungsten, or the like.

As shown in cross-sectional view 1300 of FIG. 13, the structure of FIG.12 is rotated 180 degrees and the interconnect structure 104 is bondedto a carrier substrate 102. In some embodiments, the bonding process maycomprise a fusion bonding process. In some embodiments, the carriersubstrate 102 may, for example, be a bulk substrate (e.g., a bulksilicon substrate), a silicon-on-insulator (SOI) substrate, or someother suitable substrate. In some embodiments, after performing thebonding process, a thinning process is performed on the semiconductorsubstrate 110 until the bond pad isolation structure 114 is exposed. Insuch embodiments, the thinning process reduces an initial thicknessT_(i) of the semiconductor substrate to a thickness T_(s). In someembodiments, the thickness T_(s) is equal to the height h₁ of the bondpad isolation structure 114. In further embodiments, the thinningprocess is performed by a mechanical grinding process, a CMP, some otherthinning process, or any combination of the foregoing. For example, thethinning process may be performed wholly by a mechanical grindingprocess.

As shown in cross-sectional view 1400 of FIG. 14, a dielectric structure118 is formed over the back-side 110 bs of the semiconductor substrate110. In some embodiments, the dielectric structure 118 includes one ormore dielectric layers, such as a first dielectric layer 304 a, a seconddielectric layer 304 b, a third dielectric layer 304 c, and a fourthdielectric layer 304 d. In some embodiments, the first dielectric layer304 a, the second dielectric layer 304 b, the third dielectric layer 304c and/or the fourth dielectric layer 304 d may respectively be formed byCVD, PVD, ALD, or another suitable deposition process. In furtherembodiments, the first, second, third, and fourth dielectric layers 108a-d may respectively comprise a dielectric material different from oneanother. For example, the first dielectric layer 304 a may comprisealuminum oxide, the second dielectric layer 304 b may comprise hafniumoxide, the third dielectric layer 304 c may comprise tantalum oxide, andthe fourth dielectric layer 304 d may comprise silicon dioxide. Thefourth dielectric layer 304 d may, for example, have a thickness ofabout 1,300 Angstroms. Further, a dielectric protection layer 1202 isformed over the dielectric structure 118. The dielectric protectionlayer 1202 may comprise an oxide (such as silicon dioxide) and/or mayact as a hard mask protection layer for the dielectric structure 118during subsequent processing steps. In some embodiments, the dielectricprotection layer 1202 may, for example, have a thickness of about 4,500Angstroms. In such embodiments, the thickness of the dielectricprotection layer 1202 is sufficiently large (e.g., about 4,500Angstroms), such that a thickness of the fourth dielectric layer is notreduced during subsequent processing steps (e.g., the first etch processof FIG. 15 and/or the second etch process of FIG. 16). In someembodiments, the dielectric structure has a thickness t₁ of about 2,000Angstroms.

As shown in cross-sectional view 1500 of FIG. 15, a first etch processis performed on the dielectric protection layer 1202, the dielectricstructure 118, and the semiconductor substrate 110, thereby forming plugopenings 1302. In some embodiments, the first etch process may includeperforming a wet etch process, a dry etch process, or another suitableetch process. In some embodiments, the first etch process includes:forming a masking layer (not shown) over the dielectric protection layer1202; exposing unmasked regions of the dielectric protection layer 1202and underlying layers to one or more etchants, thereby defining the plugopenings 1302; and performing a removal process to remove the maskinglayer.

As shown in cross-sectional view 1600 of FIG. 16, a second etch processis performed on the STI structure 112, the interconnect dielectricstructure 103, and the dielectric protection layer (1202). This expandsthe plug openings 1302 and exposes an upper surface of an upperconductive wire layer 108 a. In some embodiments, the second etchprocess may include performing a wet etch process, a dry etch process,or another suitable etch process. In some embodiments, the second etchprocess may include performing a blanket dry etch process on thestructure of FIG. 15. In such embodiments, the dielectric protectionlayer (1202) may be removed by the blanket dry etch process and/or thethickness of the fourth dielectric layer 304 d may, for example, beabout 1,300 Angstroms after performing the second etch process.

As shown in cross-sectional view 1700 of FIG. 17, plug structures 1702are formed within at least a portion of the plug openings 1302. In someembodiments, an upper surface of the plug structures 1702 is disposedbelow the back-side 110 bs of the semiconductor substrate 110. In someembodiments, a process for forming the plug structures 1702 includes:forming a plug material within the plug openings 1302; and performing anetch back process (e.g., a dry etch process, a wet etch process, etc.)to remove at least a portion of the plug material, thereby defining theplug structures 1702.

As shown in cross-sectional view 1800 of FIG. 18, a third etch processis performed on the dielectric structure 118 and the semiconductorsubstrate 110, thereby defining a bond pad opening 1802. The third etchprocess defines an upper surface 110 us of the semiconductor substrate110, wherein the upper surface 110 us of the semiconductor substrate 110is below the upper surface of the plug structures 1702. In someembodiments, the third etch process may include performing a wet etchprocess, a dry etch process, or another suitable etch process. In someembodiments, the third etch process includes: forming a masking layer(not shown) over the dielectric structure 118; exposing unmasked regionsof the dielectric structure 118 and the semiconductor substrate 110 toone or more etchants, thereby defining the bond pad opening 1802; andperforming a removal process to remove the masking layer.

As shown in cross-sectional view 1900 of FIG. 19, a plug removal processis performed to remove the plug structures 1702, thereby expanding thebond pad opening 1802 and exposing the upper surface of the upperconductive wire layer 108 a. In some embodiments, the plug removalprocess includes performing a wet ash process and/or a dry ash process,then performing a wet etch process.

As shown in cross-sectional view 2000 of FIG. 20, a bond pad layer 2002is formed over the structure of FIG. 19. In some embodiments, the bondpad layer 2002 may, for example, be deposited and/or grown byelectroless plating, electroplating, sputtering, or another suitabledeposition process. In further embodiments, the bond pad layer 2002 may,for example, be or comprise aluminum, copper, aluminum copper, or thelike. In some embodiments, the bond pad layer 2002 may comprise a samematerial as the conductive vias 106 and/or the conductive wires 108.

As shown in cross-sectional view 2100 of FIG. 21, a fourth etch processis performed on the bond pad layer (2002 of FIG. 20), thereby defining abond pad 116. The bond pad 116 is laterally offset from sidewalls of thesemiconductor substrate 110 and the dielectric structure 118 by adistance d₂. In some embodiments, the distance d₂ is non-zero. Infurther embodiments, the fourth etch process includes: forming a maskinglayer (not shown) over the bond pad layer (2002 of FIG. 20); exposingunmasked regions of the bond pad layer (2002 of FIG. 20) to one or moreetchants, thereby defining the bond pad 116; and performing a removalprocess to remove the masking layer.

Although FIGS. 9-13 describe forming the bond pad isolation structure114 before forming the interconnect structure 104 on the front-side 110fs of the semiconductor substrate 110, it will be appreciated thatformation of the bond pad isolation structure 114 is not limited to suchfabrication methods. For example, in some embodiments, the bond padisolation structure 114 may be formed after forming the interconnectstructure 104, wherein the bond pad isolation structure 114 extends intoan upper surface of the interconnect dielectric structure 103 (e.g., seethe integrated chip 600 of FIG. 6A). In such embodiments, the bond padisolation structure 114 may, for example, be formed after the thinningprocess of FIG. 13 but before formation of the dielectric structure 118.In yet further embodiments, the bond pad isolation structure 114 may,for example, be formed after forming the bond pad 116. In suchembodiments, the bond pad isolation structure 114 extends through thedielectric structure 118 to the front-side 110 fs of the semiconductorsubstrate 110 (not shown).

FIG. 22 illustrates a first method 2200 of forming an integrated circuitaccording to the present disclosure. Although the first method 2200 isillustrated and/or described as a series of acts or events, it will beappreciated that the method is not limited to the illustrated orderingor acts. Thus, in some embodiments, the acts may be carried out indifferent orders than illustrated, and/or may be carried outconcurrently. Further, in some embodiments, the illustrated acts orevents may be subdivided into multiple acts or events, which may becarried out at separate times or concurrently with other acts orsub-acts. In some embodiments, some illustrated acts or events may beomitted, and other un-illustrated acts or events may be included.

At act 2202, a shallow trench isolation (STI) structure is formed on afront-side of a semiconductor substrate. FIG. 9 illustrates across-sectional view 900 corresponding to some embodiments of act 2202.

At act 2204, a bond pad isolation structure is formed in thesemiconductor substrate. The bond pad isolation structure extends fromthe front-side of the semiconductor substrate to a back-side of thesemiconductor substrate. FIGS. 10 and 11 illustrate cross-sectionalviews 1000 and 1100 corresponding to some embodiments of act 2204.

At act 2206, an interconnect structure is formed on the front-side ofthe semiconductor substrate. The interconnect structure includes anupper conductive wire layer. FIG. 12 illustrates a cross-sectional view1200 corresponding to some embodiments of act 2206.

At act 2208, a dielectric structure is formed over the back-side of thesemiconductor substrate. FIG. 14 illustrates a cross-sectional view 1400corresponding to some embodiments of act 2208.

At act 2210, an etch process is performed to define plug openings in thesemiconductor substrate, thereby exposing an upper surface of the upperconductive wire layer. FIGS. 15 and 16 illustrate cross-sectional views1500 and 1600 corresponding to some embodiments of act 2210.

At act 2212, plugs are formed in the plug openings. An upper surface ofthe plugs is disposed between the front-side and the back-side of thesemiconductor substrate. FIG. 17 illustrates a cross-sectional view 1700corresponding to some embodiments of act 2212.

At act 2214, the dielectric structure and the semiconductor substrateare patterned, thereby defining a bond pad opening and an upper surfaceof the semiconductor substrate. FIG. 18 illustrates a cross-sectionalview 1800 corresponding to some embodiments of act 2214.

At act 2216, the plugs are removed, thereby expanding the bond padopening and exposing the upper surface of the upper conductive wirelayer. FIG. 19 illustrates a cross-sectional view 1900 corresponding tosome embodiments of act 2216.

At act 2218, a bond pad is formed in the bond pad openings. The bond padisolation structure continuously extends around the bond pad. FIGS. 20and 21 illustrate cross-sectional views 2000 and 2100 corresponding tosome embodiments of act 2218.

FIGS. 23-30 illustrate cross-sectional views 2300-3000 of someembodiments of a second method of forming an integrated chip including abond pad isolation structure surrounding a bond pad according to aspectsof the present disclosure. Although the cross-sectional views 2300-3000shown in FIGS. 23-30 are described with reference to a second method, itwill be appreciated that the structures shown in FIGS. 23-30 are notlimited to the method but rather may stand alone separate of the method.Although FIGS. 23-30 are described as a series of acts, it will beappreciated that these acts are not limiting in that the order of theacts can be altered in other embodiments, and the methods disclosed arealso applicable to other structures. In other embodiments, some actsthat are illustrated and/or described may be omitted in whole or inpart.

As shown in cross-sectional view 2300 of FIG. 23, the dielectricstructure 118 is formed over the semiconductor substrate 110. In someembodiments, the structure of FIG. 23 is formed as illustrated and/ordescribed in FIGS. 9-14.

As shown in cross-sectional view 2400 of FIG. 24, a first etch processis performed on the dielectric structure 118 and the semiconductorsubstrate 110, thereby forming a bond pad opening 2402. In someembodiments, the first etch process may, for example, be or comprise adry etch process, a wet etch process, or another suitable etch process.In some embodiments, the first etch process includes: forming a maskinglayer (not shown) over the dielectric structure 118; exposing unmaskedregions of the dielectric structure 118 and the semiconductor substrate110 to one or more etchants, thereby defining the bond pad opening 2402;and performing a removal process to remove the masking layer. In someembodiments, the first etch process defines an upper surface 110 us ofthe semiconductor substrate 110 disposed below the back-side 110 bs ofthe semiconductor substrate 110.

As shown in cross-sectional view 2500 of FIG. 25, a first insulatorlayer 802 is formed over the dielectric structure 118 and thesemiconductor substrate 110, wherein the first insulator layer 802 linesat least a portion of the bond pad opening 2402. In some embodiments,the first insulator layer 802 may, for example, be or comprise an oxide,such as silicon oxide, or another suitable oxide and/or has a thicknessof about 4,500 Angstroms. In further embodiments, the thickness of thefirst insulator layer 802 is sufficiently large (e.g., about 4,500Angstroms), such that a thickness of the fourth dielectric layer 304 dis not reduced during subsequent processing steps (e.g., the third etchprocess of FIG. 28).

As shown in cross-sectional view 2600 of FIG. 26, a second etch processis performed on the first insulator layer 802 and the semiconductorsubstrate 110, thereby expanding the bond pad opening 2402 and exposingan upper surface of the STI structure 112. In some embodiments, thesecond etch process includes: forming a masking layer (not shown) overthe first insulator layer 802; exposing unmasked regions of the firstinsulator layer 802 and the semiconductor substrate 110 to one or moreetchants, thereby exposing the upper surface of the STI structure 112;and performing a removal process to remove the masking layer.

As shown in cross-sectional view 2700 of FIG. 27, a second insulatorlayer 804 is formed over the first insulator layer 802 and thesemiconductor substrate 110. The second insulator layer 804 lines thebond pad opening 2402. In some embodiments, the second insulator layer804 may, for example, be formed by PVD, CVD, or another suitabledeposition process. In some embodiments, the second insulator layer 804may, for example, be or comprise an oxide, such as silicon oxide, oranother suitable oxide.

As shown in cross-sectional view 2800 of FIG. 28, a third etch processis performed on the first and second insulator layers 802, 804, the STIstructure 112, and the interconnect dielectric structure 103, therebyexposing an upper surface of the upper conductive wire layer 108 a. Insome embodiments, the third etch process may include performing a wetetch process, a dry etch process, or another suitable etch process. Infurther embodiments, the third etch process may include performing ablanket dry etch process on the structure of FIG. 27, thereby removingthe first insulator layer 802 from an upper surface of the fourthdielectric layer 304 d. In such embodiments, a thickness of the fourthdielectric layer 304 d after the third etch process may be about 1,300Angstroms.

As shown in cross-sectional view 2900 of FIG. 29, a bond pad layer 2002is formed in the bond pad opening 2402. In some embodiments, the bondpad layer 2002 may, for example, be deposited and/or grown byelectroless plating, electroplating, sputtering, or another suitabledeposition process. In further embodiments, the bond pad layer 2002 may,for example, be or comprise aluminum, copper, aluminum copper, or thelike. In further embodiments, the bond pad layer 2002 may comprise asame material as the conductive vias 106 and/or the conductive wires108.

As shown in cross-sectional view 3000 of FIG. 30, a fourth etch processis performed on the bond pad layer (2002 of FIG. 29), thereby defining abond pad 116. The bond pad 116 is laterally offset from sidewalls of thefirst and second insulator layers 802, 804 by a distance d₂. In someembodiments, the distance d₂ is non-zero. In further embodiments, thefourth etch process includes: forming a masking layer (not shown) overthe bond pad layer (2002 of FIG. 29); exposing unmasked regions of thebond pad layer (2002 of FIG. 29) to one or more etchants, therebydefining the bond pad 116; and performing a removal process to removethe masking layer.

FIG. 31 illustrates a second method 3100 of forming an integratedcircuit according to the present disclosure. Although the second method3100 is illustrated and/or described as a series of acts or events, itwill be appreciated that the method is not limited to the illustratedordering or acts. Thus, in some embodiments, the acts may be carried outin different orders than illustrated, and/or may be carried outconcurrently. Further, in some embodiments, the illustrated acts orevents may be subdivided into multiple acts or events, which may becarried out at separate times or concurrently with other acts orsub-acts. In some embodiments, some illustrated acts or events may beomitted, and other un-illustrated acts or events may be included.

At act 3102, a shallow trench isolation (STI) structure is formed on afront-side of a semiconductor substrate. FIG. 9 illustrates across-sectional view 900 corresponding to some embodiments of act 3102.

At act 3104, a bond pad isolation structure is formed in thesemiconductor substrate. The bond pad isolation structure extends fromthe front-side of the semiconductor substrate to a back-side of thesemiconductor substrate. FIGS. 10 and 11 illustrate cross-sectionalviews 1000 and 1100 corresponding to some embodiments of act 3104.

At act 3106, an interconnect structure is formed on the front-side ofthe semiconductor substrate. The interconnect structure includes anupper conductive wire layer. FIG. 12 illustrates a cross-sectional view1200 corresponding to some embodiments of act 3106.

At act 3108, a dielectric structure is formed over the back-side of thesemiconductor substrate. FIG. 14 illustrates a cross-sectional view 1400corresponding to some embodiments of act 3108.

At act 3110, the dielectric structure and the semiconductor substrateare patterned, thereby defining a bond pad opening. FIG. 24 illustratesa cross-sectional view 2400 corresponding to some embodiments of act3110.

At act 3112, a first insulator layer is formed over the dielectricstructure and the semiconductor substrate. The first insulator layerlines the bond pad opening. FIG. 25 illustrates a cross-sectional view2500 corresponding to some embodiments of act 3112.

At act 3114, the first insulator layer and the semiconductor substrateare patterned, thereby expanding the bond pad opening and exposing anupper surface of the STI structure. FIG. 26 illustrates across-sectional view 2600 corresponding to some embodiments of act 3114.

At act 3116, a second insulator layer is formed over the first insulatorlayer and the STI structure. FIG. 27 illustrates a cross-sectional view2700 corresponding to some embodiments of act 3116.

At act 3118, the first and second insulator layers, the STI structure,and the interconnect structure are patterned, thereby exposing an uppersurface of the upper conductive wire layer and expanding the bond padopening. FIG. 28 illustrates a cross-sectional view 2800 correspondingto some embodiments of act 3118.

At act 3120, a bond pad is formed in the bond pad opening. The bond padisolation structure continuously extends around the bond pad. FIGS. 29and 30 illustrate cross-sectional views 2900 and 3000 corresponding tosome embodiments of act 3120.

FIGS. 32-38 illustrate cross-sectional views 3200-3800 of someembodiments of a third method of forming an integrated chip including abond pad isolation structure surrounding a bond pad according to aspectsof the present disclosure. Although the cross-sectional views 3200-3800shown in FIGS. 32-38 are described with reference to a third method, itwill be appreciated that the structures shown in FIGS. 32-38 are notlimited to the method but rather may stand alone separate of the method.Although FIGS. 32-38 are described as a series of acts, it will beappreciated that these acts are not limiting in that the order of theacts can be altered in other embodiments, and the methods disclosed arealso applicable to other structures. In other embodiments, some actsthat are illustrated and/or described may be omitted in whole or inpart.

As shown in cross-sectional view 3200 of FIG. 32, the shallow trenchisolation (STI) structure 112 is formed on the front-side 110 fs of thesemiconductor substrate 110. In some embodiments, the STI structure 112of FIG. 32 is formed as illustrated and/or described in FIGS. 9-11.

As shown in cross-sectional view 3300 of FIG. 33, an interconnectstructure 104 is formed on the front-side 110 fs of the semiconductorsubstrate 110. The interconnect structure 104 is bonded to a carriersubstrate 102, and a dielectric structure 118 is formed over theback-side 110 bs of the semiconductor substrate 110. Further, adielectric protection layer 1202 is formed over the dielectric structure118. In some embodiments, the structure of FIG. 33 is formed asillustrated and/or described in FIGS. 12-14.

As shown in cross-sectional view 3400 of FIG. 34, an etch process isperformed on the dielectric protection layer 1202, the dielectricstructure 118, and the semiconductor substrate 110, thereby forming bondpad isolation openings 3402. In some embodiments, the etch process mayremove at least a portion of the interconnect dielectric structure 103.In some embodiments, the etch process may include performing a wet etchprocess, a dry etch process, or another suitable etch process. In someembodiments, the etch process includes: forming a masking layer (notshown) over the dielectric protection layer 1202; exposing unmaskedregions of the dielectric protection layer 1202 and underlying layers toone or more etchants, thereby defining the bond pad isolation openings3402; and performing a removal process to remove the masking layer.

As shown in cross-sectional view 3500 of FIG. 35, a first DTI layer 3502and a second DTI layer 3504 are formed over the dielectric protectionlayer 1202 and within the bond pad isolation openings (3402 of FIG. 34).In some embodiments, the first DTI layer 3502 is omitted and the secondDTI layer 3504 completely fills the bond pad isolation openings (3402 ofFIG. 34). In some embodiments, the first DTI layer 3502 may, forexample, be or comprise an oxide, such as silicon dioxide, anothersuitable oxide, or the like and/or may be formed to a thickness of about15,000 Angstroms. In further embodiments, the second DTI layer 3504 may,for example, be or comprise silicon oxynitride, another suitabledielectric material, or the like and/or may be formed to a thickness ofabout 700 Angstroms.

As shown in cross-sectional view 3600 of FIG. 36, a planarizationprocess is performed on the first and/or second DTI layers (3502, 3504of FIG. 35) thereby defining a bond pad isolation structure 114. Thebond pad isolation structure 114 may comprise a first bond pad isolationlayer 114 a and/or a second bond pad isolation layer 114 b. In someembodiments, the planarization process includes performing achemical-mechanical planarization (CMP) on the first and second DTIlayers (3502, 3504 of FIG. 35) and the dielectric protection layer 1202.In further embodiments, the planarization process may reduce a thicknessof the dielectric protection layer 1202.

As shown in cross-sectional view 3700 of FIG. 37, a bond pad 116 isformed in the semiconductor substrate 110 and is continuously surroundedby the bond pad isolation structure 114. In some embodiments, thestructure of FIG. 37 is formed as illustrated and/or described in FIGS.15-21. In further embodiments, the bond pad 116 is formed as illustratedand/or described in FIGS. 24-30. The structure of FIG. 37 may be formedby omitting the first DTI layer (3502 of FIG. 35), in which the bond padisolation structure 114 comprises the first bond pad isolation layer 114a. In some embodiments, the first bond pad isolation layer 114 a may,for example, be or comprise silicon dioxide, another suitable oxide, orthe like.

As shown in cross-sectional view 3800 of FIG. 38, a bond pad 116 isformed in the semiconductor substrate 110 and is continuously surroundedby the bond pad isolation structure 114. In some embodiments, thestructure of FIG. 38 is formed as illustrated and/or described in FIGS.15-21. In further embodiments, the bond pad 116 is formed as illustratedand/or described in FIGS. 24-30. The bond pad isolation structure 114comprises the first bond pad isolation layer 114 a and the second bondpad isolation layer 114 b. In some embodiments, the first bond padisolation layer 114 a may, for example, be or comprise silicon dioxide,another suitable oxide, or the like. In further embodiments, the secondbond pad isolation layer 114 b may, for example, be or comprise siliconoxynitride, another suitable dielectric material, or the like.

FIG. 39 illustrates a third method 3900 of forming an integrated circuitaccording to the present disclosure. Although the third method 3900 isillustrated and/or described as a series of acts or events, it will beappreciated that the method is not limited to the illustrated orderingor acts. Thus, in some embodiments, the acts may be carried out indifferent orders than illustrated, and/or may be carried outconcurrently. Further, in some embodiments, the illustrated acts orevents may be subdivided into multiple acts or events, which may becarried out at separate times or concurrently with other acts orsub-acts. In some embodiments, some illustrated acts or events may beomitted, and other un-illustrated acts or events may be included.

At act 3902, a shallow trench isolation (STI) structure is formed on afront-side of a semiconductor substrate. FIG. 32 illustrates across-sectional view 3200 corresponding to some embodiments of act 3902.

At act 3904, an interconnect structure is formed on the front-side ofthe semiconductor substrate. The interconnect structure includes anupper conductive wire layer. FIG. 33 illustrates a cross-sectional view3300 corresponding to some embodiments of act 3904.

At act 3906, a dielectric structure is formed over the back-side of thesemiconductor substrate. FIG. 33 illustrates a cross-sectional view 3300corresponding to some embodiments of act 3906.

At act 3908, a bond pad isolation structure is formed in thesemiconductor substrate and the dielectric structure. The bond padisolation structure extends from the front-side of the semiconductorsubstrate to the back-side of the semiconductor substrate. FIGS. 35 and36 illustrate cross-sectional views 3500 and 3600 corresponding to someembodiments of act 3908.

At act 3910, a bond pad is formed in the semiconductor substrate. Thebond pad isolation structure continuously extends around the bond pad.FIGS. 37 and 38 illustrate cross-sectional views 3700 and 3800corresponding to some embodiments of act 3910.

Accordingly, in some embodiments, the present disclosure relates to abond pad region laterally offset from a device region. The bond padregion includes a bond pad extending through a semiconductor substrateto an interconnect structure. A bond pad isolation structure is disposedwithin the semiconductor substrate and continuously surrounds outersidewalls of the bond pad.

In some embodiments, the present application provides a semiconductordevice structure including a semiconductor substrate having a back-sidesurface and a front-side surface opposite the back-side surface; a bondpad extending through the semiconductor substrate; and a bond padisolation structure disposed within the semiconductor substrate, whereinthe bond pad isolation structure extends from the front-side surface tothe back-side surface of the semiconductor substrate, and wherein thebond pad isolation structure continuously extends around the bond pad.

In some embodiments, the present application provides a semiconductordevice structure including a semiconductor substrate overlying a carriersubstrate, wherein photodetectors are disposed in the semiconductorsubstrate; an interconnect structure disposed between the semiconductorsubstrate and the carrier substrate, wherein an upper conductive wirelayer is disposed in the interconnect structure; a bond pad extendingthrough the semiconductor substrate to the interconnect structure,wherein the bond pad contacts the upper conductive wire layer and has atop surface disposed above the semiconductor substrate, wherein the bondpad is laterally offset from the photodetectors; and a bond padisolation structure disposed within the semiconductor substrate, whereinthe bond pad isolation structure continuously wraps around outersidewalls of the bond pad.

In some embodiments, the present application provides a method forforming a semiconductor device structure, the method includes forming abond pad isolation structure in a semiconductor substrate, wherein thebond pad isolation structure extends from a front-side surface to aback-side surface of the semiconductor substrate; forming aninterconnect structure on the front-side surface of the semiconductorsubstrate, wherein the interconnect structure includes a conductive wirelayer; patterning the front-side surface of the semiconductor substrateto define a bond pad opening and expose an upper surface of theconductive wire layer, wherein the bond pad opening is disposedlaterally between inner sidewalls of the bond pad isolation structure;and forming a bond pad in the bond pad opening, wherein the bond padextends from the semiconductor substrate to the conductive wire layer,and wherein the bond pad isolation structure continuously wraps aroundthe bond pad.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A semiconductor device structure, comprising: asemiconductor substrate having a back-side surface and a front-sidesurface opposite the back-side surface; a bond pad extending through thesemiconductor substrate; a shallow trench isolation (STI) structuredisposed along the front-side surface of the semiconductor substrate;and a bond pad isolation structure disposed within the semiconductorsubstrate, wherein the bond pad isolation structure extends from thefront-side surface to the back-side surface of the semiconductorsubstrate, wherein the bond pad isolation structure continuously extendsaround the bond pad, and wherein at least a portion of the STI structureis spaced laterally between opposing sidewalls of the bond pad isolationstructure.
 2. The semiconductor device structure of claim 1, wherein thebond pad directly contacts an upper surface and sidewalls of thesemiconductor substrate, wherein the upper surface of the semiconductorsubstrate overlies the front-side surface of the semiconductorsubstrate.
 3. The semiconductor device structure of claim 1, wherein thebond pad comprises: a conductive body directly contacting an uppersurface of the semiconductor substrate, wherein a top surface of theconductive body is vertically above the back-side surface of thesemiconductor substrate, wherein the upper surface of the semiconductorsubstrate overlies the front-side surface of the semiconductorsubstrate; and conductive protrusions extending from the conductive bodyto a point below the front-side surface of the semiconductor substrate,wherein the conductive protrusions directly contact sidewalls of thesemiconductor substrate, wherein a top surface of the conductiveprotrusions is aligned with the upper surface of the semiconductorsubstrate.
 4. The semiconductor device structure of claim 1, furthercomprising: a plurality of photodetectors disposed within thesemiconductor substrate, wherein the photodetectors are laterally offsetfrom the bond pad isolation structure by a non-zero distance; and adielectric structure disposed over the back-side surface of thesemiconductor substrate, wherein a top surface of the dielectricstructure is aligned with a top surface of the bond pad.
 5. Thesemiconductor device structure of claim 4, further comprising: atransistor disposed on the front-side surface of the semiconductorsubstrate laterally between the photodetectors and the bond padisolation structure.
 6. The semiconductor device structure of claim 4,further comprising: an interconnect structure disposed along thefront-side surface of the semiconductor substrate, wherein theinterconnect structure includes a conductive wire layer disposed withinan interconnect dielectric structure; and wherein the bond pad extendsthrough the interconnect dielectric structure and contacts theconductive wire layer.
 7. The semiconductor device structure of claim 6,wherein a bottom surface of the bond pad isolation structure is disposedbelow the front-side surface of the semiconductor substrate, wherein thebond pad isolation structure extends into the interconnect dielectricstructure.
 8. The semiconductor device structure of claim 1, wherein thebond pad isolation structure has a height greater than a height of thesemiconductor substrate.
 9. The semiconductor device structure of claim1, further comprising: a first insulator layer disposed along firstopposing sidewalls of the semiconductor substrate and an upper surfaceof the semiconductor substrate, wherein the upper surface of thesemiconductor substrate overlies the front-side surface of thesemiconductor substrate, wherein a lower surface of the bond paddirectly contacts an upper surface of the first insulator layer, whereinthe first opposing sidewalls continuously extend from the back-sidesurface to the upper surface of the semiconductor substrate; and asecond insulator layer extending from the upper surface of thesemiconductor substrate to a point above the front-side surface of thesemiconductor substrate, wherein the second insulator layer separatesthe bond pad from the semiconductor substrate.
 10. The semiconductordevice structure of claim 9, wherein upper sidewalls of the bond pad arelaterally offset from sidewalls of the first insulator layer, whereinthe second insulator layer extends from the lower surface of the bondpad along lower sidewalls of the bond pad to the point above thefront-side surface.
 11. The semiconductor device structure of claim 1,wherein the STI structure continuously extends from a first sidewall ofthe bond pad to a second sidewall of the bond pad.
 12. A semiconductordevice structure, comprising: a semiconductor substrate overlying acarrier substrate, wherein photodetectors are disposed in thesemiconductor substrate; an interconnect structure disposed between thesemiconductor substrate and the carrier substrate, wherein an upperconductive wire layer is disposed in the interconnect structure; ashallow trench isolation (STI) structure disposed within thesemiconductor substrate and continuously extending along theinterconnect structure; a bond pad extending through the semiconductorsubstrate to the interconnect structure, wherein the bond pad contactsthe upper conductive wire layer and has a top surface disposed above thesemiconductor substrate, wherein the bond pad is laterally offset fromthe photodetectors; and a bond pad isolation structure disposed withinthe semiconductor substrate, wherein the bond pad isolation structurecontinuously wraps around outer sidewalls of the bond pad, wherein theSTI structure is disposed laterally between inner sidewalls of the bondpad isolation structure, and wherein the STI structure is laterallyoffset from the inner sidewalls of the bond pad isolation structure by anon-zero distance.
 13. The semiconductor device structure of claim 12,wherein the bond pad isolation structure extends from the top surface ofthe semiconductor substrate to the interconnect structure.
 14. Thesemiconductor device structure of claim 12, wherein the inner sidewallsof the bond pad isolation structure are laterally offset from the outersidewalls of the bond pad by a non-zero distance.
 15. The semiconductordevice structure of claim 12, further comprising: a dielectric structureoverlying a top surface of the semiconductor substrate, wherein a topsurface of the dielectric structure is disposed along a substantiallystraight line; a grid structure overlying the photodetectors; andwherein the dielectric structure is disposed between the grid structureand the semiconductor substrate, and wherein a top surface of the bondpad is disposed along the substantially straight line.
 16. Thesemiconductor device structure of claim 12, wherein the bond padcomprises conductive protrusions extending through the STI structure tothe upper conductive wire layer.
 17. The semiconductor device structureof claim 16, wherein the bond pad isolation structure comprises a samematerial as the STI structure.
 18. A method for forming a semiconductordevice structure, the method comprising: forming a shallow trenchisolation (STI) structure on a front-side surface of a semiconductorsubstrate; forming a bond pad isolation structure in the semiconductorsubstrate, such that the bond pad isolation structure extends from thefront-side surface to a back-side surface of the semiconductorsubstrate, wherein outer sidewalls of the STI structure are laterallybetween inner sidewalls of the bond pad isolation structure; forming aninterconnect structure on the front-side surface of the semiconductorsubstrate, wherein the interconnect structure includes a conductive wirelayer; patterning the back-side surface of the semiconductor substrateto define a bond pad opening and expose an upper surface of theconductive wire layer, wherein the upper surface of the conductive wirelayer underlies the front-side surface of the semiconductor substrate,wherein the bond pad opening is disposed laterally between the innersidewalls of the bond pad isolation structure; and forming a bond pad inthe bond pad opening, such that the bond pad extends from thesemiconductor substrate to the conductive wire layer and is continuouslywrapped around by the bond pad isolation structure.
 19. The methodaccording to claim 18, wherein forming the bond pad comprises: forming abond pad layer over the semiconductor substrate and the interconnectstructure such that the bond pad layer fills the bond pad opening anddirectly contacts the semiconductor substrate; and patterning the bondpad layer to define the bond pad, wherein the semiconductor substratecomprises upper sidewalls and lower sidewalls underlying the uppersidewalls, wherein the upper and lower sidewalls define the bond padopening, wherein the bond pad is laterally offset from the uppersidewalls by a non-zero distance and directly contacts the lowersidewalls.
 20. The method according to claim 18, wherein the STIstructure comprises a same material as the bond pad isolation structure.